Asymptotic Scenarios for the Proton's Central Opacity: An Empirical Study

Abstract

We present a model-independent analysis of the experimental data on the ratio X between the elastic and total cross-sections from pp and p (p) over bar scattering in the c.m. energy interval 5 GeV - 8 TeV. Using a novel empirical parametrization for that ratio as a function of the energy and based on theoretical and empirical arguments, we investigate three distinct asymptotic scenarios: either the black-disk (BD) limit or scenarios above and below that limit. Our analysis favors a scenario below the BD, with asymptotic ratio X = 0.36 +/- 0.08.